This invention relates to an improved radiant solar energy collector for heating a fluid such as air having increased efficiency in the transfer of solar energy falling on the collector to the fluid, and to the method of assembling the radiant solar energy collector.
With the decreasing supply and, consequently, high cost of conventional fuels, increased attention is being given to solar energy as a substitute, at least in part, for other fuel sources for use in space heating homes and other structures. Many of the solar energy generators proposed for use in such applications are similar in their principle of operation. Typically, such a solar energy generator comprises a sheet of glass or other material which is transparent to the heat rays of the sun and which forms one side of a conduit for fluid flow. Below the transparent sheet, within the conduit, is positioned a heat-conducting sheet or plate having a coating of a suitable dark material which absorbs the solar radiant energy which passes through the transparent sheet and converts the radiant energy, causing the temperature of the plate to rise. A fluid, typically air or other gas, is passed through the conduit and is heated by contact with the energy-absorbing plate within the assembly. The heated stream of fluid which leaves the generator is then used in appropriate conventional fashion for heating a home or other building, or grain conditioning.
The suitability of a solar heat generator of this type as a substitute for other energy sources depends on the efficiency with which the solar energy is collected and transferred to the stream of fluid, and also on the amount of power necessary to keep the stream of fluid moving through the generator. It is, of course, desirable to maximize the rate of heat transfer from the energy-absorbing plate to the fluid stream while minimizing the amount of power required to pass the fluid through the solar heater. The design of a solar heat generator which will achieve simultaneously both of these objectives presents a problem, however, since the conditions which tend to increase one effect tend to reduce the other. Thus, in order to maximize the rate of heat transfer between the energy-absorbing plate and the stream of fluid, the area available for heat transfer from the plate to the fluid should be relatively high. Typical prior radiant solar energy collectors are disclosed, for example, in U.S. Pat. Nos. 4,019,494; 4,062,346; 4,178,911; 4,191,170; and 4,201,195, as well as others. While many of these systems and/or apparatus disclosed in these and other prior patents generally are operable and function to transfer the solar energy falling on the assembly to a gas stream, the industry is still striving to improve upon the efficiency and the cost of such systems and/or apparatus.
Accordingly, it is an object of the present invention to provide a low-cost, efficient, radiant solar energy collector.
A further object is to provide an improved radiant solar energy collector for collecting radiant solar energy which is readily adaptable to a surface which points in substantially any direction and inclined at optimum angles to horizontal or level while still providing the efficient collection of radiant energy.
A still further object is to provide an improved radiant solar energy collector which provides structural rigidity and lightweight construction.
Further still, it is an object to provide improved methods for fabricating such a radiant solar energy collector.